1. Field of the Invention
This invention generally relates to an arrangement for, and a method of, processing proprietary data on the active video component of a television signal, and on a plurality of lines of a picture to be displayed on a viewing screen of a television receiver, in a manner substantially invisible to a viewer, and, more particularly, to an arrangement for, and a method of, automatically identifying and verifying the airing of television broadcast programs, especially commercials.
2. Description of Related Art
It is known to automatically identify and verify the broadcast of television programs, such as first-run or syndicated feature programs and commercials, by replacing the active video component of a preselected scan line of a picture with a digital code which uniquely identifies the program. U.S. Pat. Nos. 4,547,804 and 4,639,779 teach that the identifying code is inserted on scan line 20 of a television picture. U.S. Pat. No. 4,805,020 teaches that the identifying code is inserted on scan line 22 of the television picture. Since all television receivers over-scan the screen, the first line of video information that is actually visible to a viewer is about scan line 30. Hence, the use of line 20 in the over-scan region of the television signal does not degrade the picture actually seen by the viewer, and the use of line 22 may degrade the picture on future receivers.
Although the known program verification systems are generally satisfactory for their intended purpose, the use of a single predetermined scan line to contain the identification code has not proven to be altogether satisfactory or practical. It is possible to use line 20 or 22 for other purposes, thereby limiting the available room to insert the identification code, as well as other program-related encoded information. Also, the identifying code is easily strippable, whether intentional or not, from a predetermined scan line, e.g. by a local affiliate station, thereby compromising the ability of a network broadcast station to reliably audit an affiliate's broadcast of particular programs, especially commercials.
Other known broadcast verification systems involve the use of sub-audible codes in the audio signal, for example, see U.S. Pat. Nos. 4,931,871 and 4,945,412, as well as the use of pattern recognition techniques; for example, see U.S. Pat. Nos. 4,230,990; 4,450,531; 4,739,398 and 4,843,562.
Aside from broadcast verification systems, it is known to combine other signals with television signals. For example, U.S. Pat. No. 4,647,974 encodes a trigger signal in the active video portion of a television signal in order to automatically insert local station information, such as call letters or a logo, into network supplied material, such as promotional announcements. U.S. Pat. No. 4,783,699 encodes textual information into the horizontal synchronizing pulse of a television signal. U.S. Pat. No. 4,051,532 encodes auxiliary signals, e.g., sub-titles for the hearing impaired, special notices, etc. onto the television signal. U.S. Pat. No. 4,807,031 encodes control data onto the television signal for remotely controlling interactive devices, e.g., educational aids or action toys, located in viewers' homes or schools.